Consistency transmitter

ABSTRACT

The present invention is a consistency transmitter for the measurement of consistency, viscosity, and other properties of matter. The transmitter consists of a measuring element, attached to a bearing-mounted shaft and rotated in the matter to be measured by a direct drive motor that is positioned coaxially with the measuring element and its shaft. The stator of the direct drive motor is integrated into the consistency transmitter body, its rotor into the shaft. The stator is coaxially attached to a first flange that transmits the torsional force of the motor with flexible elements to a second flange positioned on the shaft. The first and second flanges are attached to differential elements with which the phase angle between the flanges is measured using measuring elements located near the flanges. The shaft of the measuring element is bearing-mounted inside a tubular torsion shaft. The consistency transmitter can be inserted into an operating process by means of special installation equipment consisting of a shut-off valve combined with an insertion pipe. The insertion pipe includes regulating elements in such a way that they match with the matching elements on the transmitter body. With the help of regulating elements and matching elements, the transmitter can be inserted to the desired depth in the process.

BACKGROUND OF THE INVENTION

The object of the present invention is a consistency transmitter for themeasurement of consistency, viscosity, and other such characteristics ofmatter. The object of the invention is particularly the consistencyanalyzers used in the pulp and paper industry.

In rotary consistency transmitters known in the prior art, a measuringelement is rotated in the process being measured. Fibers and fillerparticles present in the measured matter, such as papermaking pulp, tendto resist the rotary motion of the measuring element. This resistingforce, which is proportional to the shear force generated by the processmatter, is measured using various torque measurement techniques andfurther converted into a variable indicating consistency. In prior artsolutions the measuring element is rotated by a single-phase orthree-phase motor that is located to the side of the rotation axis. Themotor is connected to the torsion shaft by gear, chain, or belt drivetransmission or some other power transmission system. Gearing isrequired in order to reduce the rotation speed. The use of single-phaseor three-phase motor to rotate the measuring element poses severalproblems and limitations.

A three-phase motor suited for process conditions weighs from 6 to 10kg, a single-phase motor over 10 kg. The motor has to be installed tothe side of the torsion shaft, and thus the shaft forms a lever arm andthe heavy motor causes a strong flexural and torsional stress at thepoint of the attachment to the process pipeline. Especially in processpipeworks, support structures must be installed, and these increase theinvestment cost. The bending and torsion caused by the weight of themotor also puts a strain on the torsion shaft. The weight of the motorand the required massiveness of the transmitter structure results inthat the entire device may weigh over 30 kg. Thus, handling of thedevice requires several people or a hoist.

Power transmission elements require regular service and thus causemaintenance costs. For example, a transmission belt must be inspectedfor wear every six months and replaced every few years. The transmissionbelt causes extra bending strain on the torsion shaft and will thuscontribute to more rapid wear of bearings and mechanical seals.

The rotation speed of single-phase and three-phase motors is dependenton the mains network frequency. The torque resisting the rotation of themeasuring element increases exponentially as a function of bothconsistency and rotation speed of the measuring element. When themeasuring element is rotated at a constant speed, its shape must beselected in accordance with the properties of the measured medium. Thedefining of suitable measuring elements causes additional costs and alsoincreases the number of necessary spare parts.

Motor load, and thus also rotation speed, varies due to a number ofreasons. Changes in rotation speed cause the measurement signal to driftand thereby complicate the measurement. Rotation speed changes whenconsistency, i.e. the shear force resisting measuring element rotation,changes. The rotation speed changes also due to changes in the frictionof the torsion shaft bearings and mechanical seals. The friction forcesin mechanical seals are affected by process pressure: a higher pressureforces the sealing surfaces more tightly against each other and thusincreases friction. In cage induction motors, the backward slip thataffects rotation speed is also dependent on motor load.

Most cage induction motors have a fixed direction of rotation, and asconsequence, unwanted materials caught to the measuring element can onlybe removed if the device is first pulled out of the process.

Single-phase and three-phase motors require high-voltage operating powerand must be well enclosed to protect them from moisture and the processenvironment. High voltage increases electrical safety requirements, anda qualified electrician is needed to install a three-phase motor to thepower network or to disconnect it. Several single-phase and three-phaseoperating voltages are known in the world, and thus a separate motortype has to be chosen for each voltage. The need to provide fordifferent operating voltages increases the variety of models and spareparts that a manufacturer has to offer.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a consistencytransmitter where the measuring element is rotated by a direct drivemotor. The rotor of the direct drive motor is coaxially attached to thetorsion shaft of the measuring element, while its stator is attached tothe support structure of the torsion shaft in such a way that the rotorand stator are coaxial. The direct drive motor is driven by controlelectronics in such a way that its rotation speed can be changed with aprogram. The torque caused by the process matter is transmitted alongthe shaft to a differential element, which consists of two coaxialflanges between which a phase shift resisted by spring elements isgenerated. Spring elements are attached in pairs to the flanges so thatthe phase shift is resisted by several pairs of spring elements. Eachspring element pair is balanced so as to ensure that the phase shiftwill be directly proportional to the torque effective over the measuringelement and measurable by using opto-electronic or electromagneticdevice.

The condition of the bearings, seals, and other elements of theconsistency transmitter can be monitored by observing the powerconsumption of the direct drive motor. The input power of the motor isconsumed by the friction of the device's mechanical parts such asbearings and seals of the torsion shaft and by the rotation of themeasuring element. The input power of the measuring element can becalculated from its torque, and when this input power is reduced fromthe total output, the result gives the power required to rotate thetorsion shaft. The calculated input power of the torsion shaft willincrease for example when bearings are worn or defective, and if thisvalue exceeds a preset limit, the operator can be alerted.

The consistency transmitter can be installed into an operating process,and its insertion distance is adjustable. The drive shaft and thetorsion shaft inside it are sealed in such a way that process mediumcannot get in touch with the seal ring between the shafts. This sealingarrangement eliminates the effects of process medium on the seals andtheir friction.

A direct drive motor weighs less than 1 kg and thus causes anessentially smaller flexural strain than the motors according to theprior art. The entire consistency transmitter is a lightweight devicethat is easy to handle and install, even by a person working alone.

A direct drive motor does not include separate power transmissionelements, e.g. belt or belt pulleys, to rotate the measuring element.The load on the bearings is substantially smaller, as the forces causedby power transmission are clearly lower. A direct drive motor can beintegrated into the consistency transmitter, and its rotating parts canbe balanced with regard to the rotating shaft.

The speed of a direct drive motor can be set to a desired level with aprogram. Constant feedback of motor rotation speed is obtained, andcontrol electronics keep the rotation speed constant. With one variablestabilized, a more accurate measurement signal is obtained. For optimalconsistency measurement it is advantageous, if the speed of themeasuring element can be selected so that the desirable speed can beused in each measurement application. For example at high consistenciesthe rotating speed can be reduced, so as to expand the consistencymeasuring range of a measuring element. Freely selectable rotating speedmeans that only one measuring element is needed in order to measureconsistency throughout the consistency range used in the pulp and paperindustry, typically from 0.5% through 16%.

Unwanted materials (e.g. plastic shreds) may be present in the processand when these get caught to the measuring element, they cause errors inthe measurement reading. By reversing the rotation direction, materialscaught to the measuring element can be loosened without uninstalling theentire transmitter from the process. Moreover, the verification of themeasuring element's zero point or automatic zero point calibration canbe done by rotating the measuring element back and forth. If themeasuring element is symmetrical, its zero point is the average of thetorque readings measured when it is rotated back and forth; if it isasymmetrical, the zero point is between these torque readings. The zeropoint is specific for each measuring element and can be determined bymeans of laboratory tests. In some applications calibration can becarried out during operation by placing a calibration brake on the endof the rotation axis of the measuring element.

A direct drive motor's operating voltage is low, e.g. 48 V, which isadvantageous as for its electrical safety. The cabling costs of alow-voltage power supply are considerably lower. Moreover, theelectrotechnical components of a direct drive motor can be assembled inthe same housing as the measurement electronics of the device, whichreduces the investment and maintenance costs.

The present invention solves the problems listed above and correctsshortcomings of the prior art. It brings about a direct-drive poweredconsistency transmitter that is lightweight, easily controlled byprogram, has a low operating voltage, and is economical in total costs.

The above-mentioned advantages will be achieved by using a consistencytransmitter according to the invention characterized by the featuresdescribed in the independent claims.

The object of the invention is a consistency transmitter for themeasurement of consistency, viscosity, and other characteristics ofmatter. The transmitter consists of a measuring element attached to abearing-mounted shaft, which measuring element is rotated in the matterbeing measured. The measuring element is rotated by a direct drive motorthat is positioned coaxially with the measuring element and its shaft.The stator of the direct drive motor is integrated into the body of theconsistency transmitter, its rotor into the shaft. The rotor isconnected to a first flange positioned coaxially with it, by whichflange the torsional force of the motor is guided to the second flangeon the shaft. The elements between the flanges function as torsionalforce transmission elements. Differential elements in connection withthe first and second flanges indicate the phase angle between them.Close to the flanges there are means for measuring the phase anglebetween the flanges. The shaft of the measuring element isbearing-mounted inside a tubular torsion shaft. The drive shaft in turnis bearing-mounted inside the transmitter body and sealed at its frontend to prevent the entry of process medium inside the device. The driveshaft is sealed in such a way that it can be lubricated and cooled witheither water the pressure of which is higher than process pressure orwith low-pressure circulating water. In connection with the torsionshaft are also means for sealing, which prevent the entry of processmedium inside the transmitter. The task of the torsion shaft is to movethe differential elements and their measuring elements further away fromthe process of variable temperatures. The coupling between torsion shaftand differential elements mechanically protects the differentialelements against shocks and overload situations. In addition, thetorsion shaft serves to eliminate from the measurement the torque lossescaused by the friction of bearings and sealings. The measuring shaft hasa small diameter in order to reduce its torque loss. The body of theconsistency transmitter is elongated in shape so as to ensure that themeasuring element can be inserted sufficiently far into the process. Theconsistency transmitter can be inserted into an operating process byusing dedicated installation equipment. The installation equipmentconsists of a shut-off valve combined with an insertion pipe. Theinsertion pipe contains regulating elements that correspond withmatching elements on the transmitter body. With the help of theregulating and matching elements, the transmitter can be inserted intothe required depth in the process. The insertion distance of thetransmitter can be changed while the process is operating, and it can besecured in position by using suitable locking elements.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the present invention will be described in more detailby some advantageous embodiments and with reference to the attacheddrawings.

FIG. 1 shows a consistency transmitter according to the invention, inside view and in cross section;

FIG. 2 shows a cross section of the measuring head of the deviceillustrated in FIG. 1;

FIG. 3 shows a cross section of the drive end of the device illustratedin FIG. 1;

FIG. 4 shows one possible method with which a device according to theinvention can be inserted into a process; and

FIG. 5 shows the differential elements and calibration equipment of oneapplication of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1-5 illustrate a consistency transmitter according to theinvention, which consists of measuring element 1: torsion shaft 2;bearing and sealing element 3; differential elements 4; drive shaft 5;clamping element 6; clamping and sealing elements 7; rotor 8; stator 9;stator base 10; drive shaft body 11; end piece of drive shaft body 12;sealing elements 13; flange 14; sealing elements 15 and 19; bearingelements 16, 17 and 18; coupling element 20, insertion pipe 21; valve22; sealing elements 23 and clamping elements 24 and 25; controlelectronics 26; and calibration equipment 27.

Measuring element 1 consists of motion-resisting elements 1 a attachedto arms 1 b. Measuring element 1 is attached with mounting element 1 cto the end 2 a of the torsion shaft 2, which is preferablyself-centering. Torsion shaft 2 is bearing-mounted inside drive shaft 5,using bearing and sealing element 3 at the measuring end and bearingelement 18 at the drive end 2 b, which element is advantageously anannular ball bearing. The outer shell of bearing 18 matches with theshoulder of sleeve 4 b 1 located on the first flange of the differentialelement, and is axially locked into the shoulder with clamping element6, which is advantageously a threaded sleeve. Element 3, either slidebearing or roller bearing, is combined with sealing elements 3 a toprevent the entry of process media into the device. Calibrationequipment 27, including pulling groove 27 a, are incorporated in the endof the torsion shaft. A calibration brake (not shown) can be insertedinto groove 27 a via hole 27 b through part 10 c, As shown in FIG. 5.

To the drive end 2 b of torsion shaft 2 is attached the second flange 4a of the differential element 4, the flange including a slot plate 4 e.Slot plates 4 e, located on the outer shells of flanges 4 a and 4 b,consist of a thin plate with a great number of radial slots (not shown).The first flange 4 b of differential element 4 is located next to sleeve4 b 1, which is positioned coaxially inside rotor 8, so that flanges 4 aand 4 b and thus also slot plates 4 e face each other. Flexible elements4 c, e.g. springs, located between flanges 4 a and 4 b transmit thetorsional force from rotor 8 to torsion shaft 2. Differential elements 4include elements 4 f with which the tangential phase shift between slotplates 4 e can be measured. The elements 4 f are advantageously suitableopto-electronic or electromagnetic sensors, the signal of which isconverted with electronic control devices 26 to correspond to thecurrently effective torque. Elements 4 f are attached to plate 4 d whichin turn is attached to stator body 10. Plate 4 d is inserted through ahole on stator body, and the hole is closed with cover 4 g and clampingelements 4 h.

In one advantageous embodiment of the invention, as shown in FIG. 5,flexible elements 4 c are mounted on pins 4 c 2 that are fastened toflange 4 b. Pins 4 c 2 are parallel with the longitudinal axis of thedevice, and they protrude through holes 4 c 1 in flange 4 a so far thatflexible elements 4 c can be fastened to their ends. Flexible elements 4c are connected at their second ends in pairs to slide element 4 c 3that is placed between them, which slide element passes through fixingpin 4 c 4 located on flange 4 a. Flexible elements 4 c are firstconnected to pins 4 c 1 and to slide element 4 c 3, which will thensettle in a balanced state as determined by elements 4 c. The slideelement is then locked to mounting pin 4 c 4 with clamping element 4 c5. Flexible elements 4 c are positioned in such a way that they canreceive and attenuate the phase shift generated between flanges 4 a and4 b. Holes 4 c 1 in flange 4 a are sufficiently large in diameter so asnot to hinder said phase shift. Holes 4 c 1 and pins 4 c 2 passingthrough them act as mechanical overload protection, protectingdifferential elements 4 from excessive stress. In an overload situation,pins 4 c 2 will receive stroke-like stress when hitting against theedges of holes 4 c 1.

Drive shaft 5 is ad advantageously tubular in shape so that torsionshaft 2 can be positioned inside it. Drive shaft 5 is bearing-mounted inthe drive shaft body 11 with bearing elements 16 and 17. Element 16 isadvantageously an annular ball bearing, and element 17 consists of apair of angular contact ball bearings. Bearing elements 16 and 17 aresealed with sealing elements 15 and 19. Element 15 advantageouslyconsists of two facing radial seals, element 19 of one radial seal.Element 15 seals the device against process media and also seals thebearing lubricant inside. Element 19 prevents the entry of lubricantinside differential element 4. At its drive end, shaft 5 is also sealedagainst process medium with sealing elements 13 that are located in theend piece of drive shaft body 12.

Drive shaft 5 is closed at the measuring head end with a sleeve-shapedclamping element 7 attached to the shaft. Clamping element 7 is enclosedby an elastic shell 7 b secured with clamping elements 7 c that areplaced over clamping element 7 and shaft 2. The clamping elements 7 care for example locking rings. Shell 7 b is elastic between fasteningelements 7 c and thus allows the phase shift that the measured torquegenerates between drive shaft 5 and torsion shaft 2.

The rotor 8 of the direct drive motor is attached on the outer shell ofsleeve 4 b 1 of the first differential element flange using frictionmounting or mechanically closed form joint. The rotor includes ring 8 a,which contains direct drive motor control devices 8 b that arecontrolled with control electronics 26. Stator 9 is located insidestator base 10 that is positioned coaxially with the rotor. Rotor 8,stator 9, and control devices 8 b are advantageously components of acommercially available frameless, brushless direct drive motor.

Stator base 10 consists of a sleeve-shaped body 10 b that is enclosedusing covers 10 a and 10 c. Enclosed cover 10 c closes the base at thedrive end and is attached with fastening element 10 d, advantageously athread. Cover 10 a at the measuring head side is centered and fastenedto body 10 b with elements 28. Also drive shaft body 11 is attached withelements 27 to the opposite side of cover 10 a. Cover 10 a limits inaxial direction bearing element 17, and the above-mentioned sealingelement 19 is mounted against its inner shoulder. If necessary, coolingelements such as ribs or channels (not shown) can be arranged onto theouter shell of stator base 10 b.

Drive shaft body 11 consists of an elongated and sleeve-like part 11 athat is closed at the end by the end piece 12 of drive shaft body. Whenthe device is installed to process, the outer surface of part 11 afunctions as a sealing surface. Sealing elements 11 c are locatedbetween end piece 12 and part 11 a, and end piece 12 is fastened to thebody 11 with fastening element 11 b. The fastening element 11 b isadvantageously a thread. Part 11 a is provided with channels for sealingwater or for other cooling and cleaning medium.

End piece 12 contains process medium sealing elements 13 that consist ofring 13 a and rings 13 b that limit it in both directions. Ring 13 arotates with drive shaft 5 while rings 13 b remain static, whereby thefacing surfaces of rings 13 a and 13 b provide the sealing effect. Rings13 a and 13 b are made of materials suitable for end face seals.

Rings 13 a and 13 b are sealed against drive shaft 5, end piece 12 andflange 14 using sealing elements 13 c. Annular flange 14 is locatedbetween drive shaft body 11 and end piece 12.

Installation elements include coupling element 20, insertion pipe 21,valve 22, sealing elements 23, and clamping elements 24 and 25. Couplingelement 20 is advantageously a conical sleeve that can be fastened toprocess pipes of different sizes. Part 20 is fastened to valve 22 thatconsists of a first flange 22 a and a second flange 22 c, between whichthe closing element body 22 b is placed. Flanges 22 a and 22 c arefastened to each other with elements 25, which are advantageouslyscrews. The consistency transmitter can be inserted into hole 22 g thatpasses through the flanges. Hole 22 g, and the body of consistencytransmitter drive shaft 11, are sealed with sealing elements 23. Closingdevice 22 d, located inside the closing element body, can be moved usingarm 22 f and handle 22 e. The arm 22 f is advantageously a threaded barand the handle is a handwheel or other corresponding device. Closingelement 22 d is sealed between flanges 22 a and 22 c with suitablesealing methods (not shown) and includes plate 22 d 1 that closes hole22 g passing through flanges 22 a and 22 c. The valve closes when theclosing plate 22 d 1 is moved so that it fully coincides with hole 22 g.Insertion pipe 21 is attached to second flange 22 c with elements 24,and the consistency transmitter (body 11) can be pushed through theinsertion pipe into an operating process. Pipe 21 is provided withpitched grooves 21 a that reach all the way to the end of pipe 21 andfunction as regulating elements. A torsion arm 21 b, attached to body11, travels inside each groove and functions as the matching element ofthe regulating elements. Insertion pipe 21 is sufficiently long toensure that body 11 closes hole 22 g when valve 22 is open. Torsion arm21 b, traveling in groove 21 a, receives the axial force caused byprocess pressure when the consistency transmitter is being installed toprocess or removed from it.

In one advantageous embodiment of the invention, the regulating elementis thread 21 a constructed on the outer shell of body 11, while pegs 21b placed in the thread act as the matching elements. Insertion pipe 21is split longitudinally so that it can be clamped around the outer shellof body 11 using clamping collars (not shown). The consistencytransmitter can then be steplessly screwed deeper into the requireddistance by using for example a trapezoidal thread 21 a.

One device according to the invention functions as follows: Consistencytransmitter is inserted into insertion pipe 21 in such a way thattorsion arm 21 b is in groove 21 a. Torsion arm 21 b is turned in thegroove until the transmitter body 11 is deep enough to close hole 22 g.Valve 22 is opened, and the axial force caused by the process pressurewill be effective on the transmitter. Torsion arm 21 b is turnedfurther, and the transmitter moves against process pressure. The torsionarm is turned until the device reaches the required insertion depth inthe process, after which it is secured in position with locking devices(not shown). The consistency transmitter can be extracted from processin reverse order. The transmitter is operated by means of control andautomation equipment that is advantageously located in a separatehousing. A direct drive motor (8, 9) rotates the measuring element 1 ata program-selectable rotation speed that is set and controlled bycontrol electronics 26 according to the prevailing process conditions.The rotation of measuring element 1 can also be reversed with a programfor cleaning or calibration purposes. Torque is transmitted from driveshaft 5 to torsion shaft 2 through flexible elements 4 c located betweenflanges 4 a and 4 b. The process medium resists the rotation and causesa phase shift, dampened by elements 4 c, between torsion shaft 2 anddrive shaft 5. This phase shift is measured with the help of slot plates4 e of differential elements using opto-electronic or electromagneticdevices, and it is further converted by a program into a signalcorresponding to the measured variable, such as consistency. Drive shaft5 rotates at the speed of the direct drive motor, receiving the losstorque caused by bearings 16 and 17 and sealings 13, 15 and 19, whichthus cannot affect the measurement results. In demanding processconditions this loss torque can be relatively large. Thus the measuredphase shift includes the torque generated by the process medium and thelosses caused by the torsion shaft bearing and sealing elements (3 a,18, 7 b). These losses are very small, as the relative motion of thetorsion shaft and the elements in contact with it is small. Said lossescan also be reduced by dimensioning the torsion shaft so that itsdiameter is as small as possible.

The drawings and description are only intended to illustrate the presentinvention. Its details may vary within the limits set by the attachedclaims and by the description of the invention. For example, thestructure of sealing elements 13 may differ from that described above,depending on the manufacturer. Moreover, it is clear to the man skilledin the art that embodiments of the invention may vary within theoperating environment, customer needs, and solutions adopted inmanufacturing.

1. Consistency transmitter capable of measuring the consistency andviscosity of matter, comprising a measuring element fastened to an endof a torsion shaft, a drive shaft, differential elements connecting thetorsion shaft and drive shaft to each other, and an insertion pipe andvalve combined with the insertion pipe for the purpose of inserting theconsistency transmitter into a process to be measured while said processis operating, wherein: a motor of the consistency transmitter comprisesa direct drive stator and rotor, rotation axes of which are coaxial withthe rotation axes of the measuring element, torsion shaft, differentialelements, drive shaft and the insertion pipe, whereby the consistencytransmitter has no separate motor; instead the stator is integrated intoa stator base and the rotor is integrated into drive shaft, so that thedrive shaft also functions as a rotor shaft; the drive shaft is fit withdrive shaft bearings on a drive shaft body and the drive shaft bearingsare also arranged to act as rotor bearings; the drive shaft and therotor have common covers and seals; the drive shaft is comprised of onepiece and comprises an end that protrudes into the process beingmeasured; and the torsion shaft is bearing-mounted inside the driveshaft.
 2. The consistency transmitter according to claim 1, wherein: theconsistency transmitter is arranged to be inserted into a pressurizedprocess using installation equipment comprising a shut-off valve and theinsertion pipe combined with the consistency transmitter; and theconsistency transmitter is arranged to be inserted to a required depthinto the pressurized process, and its depth is arranged to be adjustedby regulating elements and their matching elements on a transmitterbody.
 3. The consistency transmitter according to claim 2, wherein: thedrive shaft is closed at a measuring head end with a sleeve-shapedelement around which an elastic shell is secured with clamping elementsplaced over the element and over the torsion shaft, in order to preventprocess matter from entering a bearing element and at least one sealingelement of the drive shaft; and said elastic shell is flexible so as toallow a phase shift between drive shaft and torsion shaft.
 4. Theconsistency transmitter according to claim 2, wherein in a drive end ofthe torsion shaft is a pulling groove to which a calibration brake isarranged to be attached in order to calibrate the consistencytransmitter while the process is operating.
 5. The consistencytransmitter according to claim 2, wherein a maintenance of the driveshaft bearings and seals is arranged to be monitored by measuring apower transmitted by the rotor and stator, which power is arranged to becompared with an input power of the measuring element so as to detectchanges taking place in a condition of the drive shaft bearings andseals.
 6. The consistency transmitter according to claim 1, wherein: thedrive shaft is closed at a measuring head end with a sleeve-shapedelement around which an elastic shell is secured with clamping elementsplaced over the element and over the torsion shaft, in order to preventprocess matter from entering a bearing element and at least one sealingelement of the drive shaft; and said elastic shell is flexible so as toallow a phase shift between the drive shaft and the torsion shaft. 7.The consistency transmitter according to claim 6, wherein in a drive endof the torsion shaft is a pulling groove to which a calibration brake isarranged to be attached in order to calibrate the consistencytransmitter while the process is operating.
 8. The consistencytransmitter according to claim 2, wherein a rotation of the measuringelement is arranged to be program-controlled with control electronicsaccording to the needs of each process, and a plurality ofmotion-resisting elements of measuring element are arranged in such away that a consistency measurement range of a consistency transmitterprovided with said measuring element is from 0.5 to 16%; and a rotationspeed of the measuring element is arranged to be adjusted according to aprocess matter, either before or during the process; a rotationdirection of the measuring element is arranged to be repeatedly reversedin order to free the measuring element from disturbing particles; andthe rotation direction of the measuring element is arranged to berepeatedly reversed in order to calibrate a signal generated by themeasuring element.
 9. The consistency transmitter according to claim 6,wherein a rotation of the measuring element is arranged to beprogram-controlled with control electronics according to the needs ofeach process, and a plurality of motion-resisting elements of measuringelement are arranged in such a way that a consistency measurement rangeof a consistency transmitter provided with said measuring element isfrom 0.5 to 16%; and a rotation speed of the measuring element isarranged to be adjusted according to a process matter, either before orduring the process; a rotation direction of the measuring element isarranged to be repeatedly reversed in order to free the measuringelement from disturbing particles; and the rotation direction of themeasuring element is arranged to be repeatedly reversed in order tocalibrate a signal generated by the measuring element.
 10. Theconsistency transmitter according to claim 6, wherein a maintenance ofthe drive shaft bearings and seals is arranged to be monitored bymeasuring a power transmitted by the rotor and stator, which power isarranged to be compared with an input power of the measuring element soas to detect changes taking place in a condition of the drive shaftbearings and seals.
 11. The consistency transmitter according to claim1, wherein in a drive end of the torsion shaft is a pulling groove towhich a calibration brake is arranged to be attached in order tocalibrate the consistency transmitter while the process is operating.12. The consistency transmitter according to claim 11, wherein arotation of the measuring element is arranged to be program-controlledwith control electronics according to the needs of each process, and aplurality of motion-resisting elements of measuring element are arrangedin such a way that a consistency measurement range of a consistencytransmitter provided with said measuring element is from 0.5 to 16%; anda rotation speed of the measuring element is arranged to be adjustedaccording to a process matter, either before or during the process; arotation direction of the measuring element is arranged to be repeatedlyreversed in order to free the measuring element from disturbingparticles; and the rotation direction of the measuring element isarranged to be repeatedly reversed in order to calibrate the signalgenerated by the measuring element.
 13. The consistency transmitteraccording to claim 11, wherein a maintenance of the drive shaft bearingsand seals is arranged to be monitored by measuring a power transmittedby the rotor and stator, which power is arranged to be compared with aninput power of the measuring element so as to detect changes takingplace in a condition of the drive shaft bearings and seals.
 14. Theconsistency transmitter according to claim 1, wherein a rotation of themeasuring element is arranged to be program-controlled with controlelectronics according to the needs of each process, and a plurality ofmotion-resisting elements of the measuring element are arranged in sucha way that a consistency measurement range of the consistencytransmitter provided with said measuring element is from 0.5 to 16%; anda rotation speed of the measuring element is arranged to be adjustedaccording to a process matter, either before or during the process; arotation direction of the measuring element is arranged to be repeatedlyreversed in order to free the measuring element from disturbingparticles; and the rotation direction of the measuring element isarranged to be repeatedly reversed in order to calibrate a signalgenerated by the measuring element.
 15. The consistency transmitteraccording to claim 14, wherein a maintenance of the drive shaft bearingsand seals is arranged to be monitored by measuring a power transmittedby the rotor and stator, which power is arranged to be compared with aninput power of the measuring element so as to detect changes takingplace in a condition of the drive shaft bearings and seals.
 16. Theconsistency transmitter according to claim 1, wherein a maintenance ofthe drive shaft bearings and seals is arranged to be monitored bymeasuring a power transmitted by the rotor and stator, which power isarranged to be compared with an input power of the measuring element soas to detect changes taking place in a condition of the drive shaftbearings and seals.
 17. The consistency transmitter according to claim1, wherein: flexible elements that are part of the differential elementsare fastened to pins attached to a second flange; said pins are parallelto a longitudinal axis of the consistency transmitter and protrudethrough holes in a first flange so far that flexible elements can beattached to their ends; and at respective second ends thereof, theflexible elements are connected as pairs to a slide element betweenthem, the slide element being arranged to pass through a fixing pin onthe second flange in such a way that the slide element is in a balancedstate determined by elements.
 18. The consistency transmitter accordingto claim 17, wherein the flexible elements are positioned in such a waythat they receive a torsion strain generated between the first andsecond flange by the consistency and viscosity, of the matter acting onthe measuring element ; this strain creates a measurable phase shift,directly proportional to a torsional force, between said flanges. 19.The consistency transmitter according to claim 18, wherein the holes andthe pins passing through them are arranged so as to act as overloadprotection, whereby said pins receive the strain as they collide againstedges of the holes.
 20. The consistency transmitter according to claim17, wherein the holes and the pins passing through them are arranged soas to act as overload protection, whereby said pins receive the strainas they collide against edges of the holes.